This invention relates to a gas generator, particularly for use with an inflatable impact cushion for protecting a passenger in a motor vehicle from injury, the generator comprising a housing, a combustible liquid gas mixture located therein for generating gas under pressure, and an ignitable ignition charge.
This invention also relates to a gas generator for inflating an inflatable impact cushion to protect an occupant of a motor vehicle from injury which has a housing, a combustible gas-producing liquid gas mixture for generating pressure gas accommodated in the housing, an ignitible ignition charge for igniting the liquid gas mixture and a combustion chamber arranged in the housing in which the liquid gas mixture burns, with the resulting pressure gas emerging from the combustion chamber by way of at least one outlet opening in a housing wall.
With the gas generators used at present for inflatable impact cushions of motor vehicles (also termed "Airbags") a charge in the form of solid tablets or discs is used as a combustible gas-producing material. On ignition, this solid gas-generating charge produces the useful pressure gas or gas under pressure for inflating the impact cushion. A disadvantage caused by combustion of solid gas-producing materials is that quite a large amount of slag is formed during the combustion, which represents more than 50% of the mass of the gas-generating gas charge used. Because of the slag and dust formation during combustion, expensive filter stages in the gas generator are necessary in order to hold back the slag and the dust particles. Otherwise when these particles emerge, the impact cushion would be damaged and the occupants of the vehicle placed in danger.
As an alternative to generators containing solid materials, there are generators containing compressed gases or air. In order to form a sufficient volume of gas, very high charge pressures are necessary as cooling takes place on discharge of the gases and no increase in volume can be achieved by exothermic reactions such as with solid matter mixtures.